The bird is completely dark brown except for a variable patch of white near the bill base, which is black. It breeds on islands throughout the southern oceans. It’s distinguished from the Sooty Shearwater and Short-tailed Shearwater by the all-dark underwing, the thick stubby bill, and different jizz. Also, the similar Flesh-footed Shearwater has a light, pinkish colored bill. Petrels in the genus Procellaria are bigger and have a less bouncing flight.